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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    let arr=[23,44,566,542,78];
    console.log(arr[2]); //21
    let arr2 =['tom',34.4,ture,,, ];
    console.log(arr2[4]);
    arr2[4] =null;
    console.log(arr2[4]);
    //遍历数组
    console.log(arr.length); //获取数组长度
    for(let i =0;i<arr.length;i++){
        console.log(arr[i]);

    }
    //score=[]
    let score=[89,67,59,90,54,77,83,88.5,43,10,68];
    let max =score[0];
    let sum=0;
    for(let i=0; i<score.length;i++){
        if(score[i]>max){
            max=score[i];
        }
        sum +=score[i];
    
    }
    console.log('最大值是:'+max);
    console.log(sum/score.length);
    //
    console.log('--------');
    score[1000]=88;
    confirm.log(score[1000]);
    console.log(score.length);
    for(let i =0;i<score.length;i++);
</script>
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